Very often in connection with the deposition of various materials or substances, such as, for example, hot melt adhesive material, onto an underlying substrate, it is desired to deposit or apply different types of adhesive materials, compositions, or the like, or adhesive coatings or materials, comprising different thickness dimensions or patterns, in an overlying or overlapping manner onto the underlying substrate. For example, depending upon the particular structural requirements of the particular product being fabricated or manufactured, the hot melt adhesive materials are required to be deposited upon the underlying substrate in accordance with predetermined patterns and at predetermined times during the deposition procedure or process. Such deposition techniques may theoretically be accomplished, for example, by means of a system employing two different contact die applicators, however, this has not in fact proven to be practically viable in view of the fact that when the second contact die applicator deposits the second adhesive, material, or coating onto the underlying substrate, the first material, adhesive, coating, or substance tends to be wiped off the underlying substrate. Accordingly, it has been contemplated that another mode for achieving such deposition techniques may be accomplished, for example, by means of a system wherein the first adhesive coating or substance is applied by means of a contact die applicator, however, the second adhesive coating or substance is applied by means of a spraying operation. However, this type of system is relatively complex in view of the fact that two different applicators must be utilized, both pneumatic and hydraulic systems need to be employed, and the actual handling, or relative movement of the substrate, with respect to the applicators, becomes relatively complicated.
A need therefore exists in the art for a new and improved dispensing system, in particular, for a hot melt adhesive dispensing system, wherein multiple different types of materials, substances, adhesives, coatings, or the like, or multiple different materials, adhesives, coatings or substances, comprising, for example, different thickness dimensions or patterns, can be deposited or applied in an overlying or overlapping manner onto an underlying substrate during a single pass of the underlying substrate with respect to the applicator or head. A need also exists in the art for a new and improved dispensing system, in particular, for a hot melt adhesive dispensing system, wherein the multiple different hot melt adhesive materials can be deposited upon the underlying substrate in accordance with predetermined patterns, and at predetermined times during the deposition procedure or process, depending upon the particular structural requirements of the particular product being fabricated or manufactured so as to effectively enhance the fabrication or manufacturing capabilities of the overall product assembly line. Still further, a need exists in the art for a new and improved dispensing system, in particular, for a hot melt adhesive dispensing system, wherein multiple different adhesive deposition or application procedures are permitted to effectively be accomplished simultaneously so as to effectively simplify and shorten the overall assembly line and production times required for the fabrication or manufacture of various different particular products.